Abstract: Based on meteorological data from 2000 to 2009，including daily temperature，relative humidity，sunshine hours and wind speed of 124 meteorological stations in arid region of northwest China，crop reference evapotranspiration (ET0) were calculated by using of the Penman Monteith formula，which was nominated by FAO in 1998 and Kriging method Furthermore，spatial transfer of the centroids of daily mean evapotranspiration zone (≥0.4mm) in crop growing season，from April to September，was analyzed by function of spatial analysis of GIS.The results showed that the centroids of daily mean evapotranspiration zone (≥0.4mm) described fluctuating two times from east to west and located in the middle region finally.The migration paths of centroids showed from dispersed to concentrated，and then dispersed.The plane distance between starting and end centroid was longest in April，followed by July，September，June and August，and shortest in May.The destination for centroid of every month during crop growing season was different，but most located in Inner Mongolia .Furthermore，the sunshine duration was followed，and the stations where an evapotranspiration change was sensitive to relative humidity account for the minority.The results could provide important information for the research on developing active adaptation measures to ensure food security under climate change.The results were widely acknowledged in agricultural drought monitoring，water resources management and assessment.

Key words: Reference crop evapotranspiration, Spatial pattern, Spatial evolution, Sensitive stations, Northwest China